40 C.F.R. § 59.506
How do I demonstrate compliance if I manufacture multi-component kits?
(a) If you manufacture multi-component kits as defined in § 59.503, then the Kit PWR must not exceed the Total Reactivity Limit.
(b) You must calculate the Kit PWR and the Total Reactivity Limit as follows:
(1) KIT PWR = (PWR
(2) Total Reactivity Limit = (RL
(3) Kit PWR ≤Total Reactivity Limit.